Molecular sieve materials, both natural and synthetic, have been demonstrated in the past to be useful as adsorbents and to have catalytic properties for various types of hydrocarbon conversion reactions. Certain molecular sieves, such as zeolites, silicoaluminophosphates, aluminophosphates, and mesoporous materials, are ordered, porous crystalline materials having a definite crystalline structure as determined by X-ray diffraction. Within a crystalline molecular sieve material there are cavities which may be interconnected by channels or pores. These cavities and pores are uniform in size within a specific molecular sieve material. Because the dimensions of these pores are such as to accept for adsorption molecules of certain dimensions while rejecting those of larger dimensions, these materials have come to be known as “molecular sieves” and are utilized in a variety of industrial processes.
U.S. Pat. No. 5,591,421 discloses a zinco(alumino)silicate molecular sieve designated SSZ-41 and its synthesis using a polymethylene diquat compound as a structure directing agent, such as α,ω-di(N-methylpiperidine)polymethylene dicationic compounds and α,ω-di(1,4-diazabicyclo[2.2.2]octane)polymethylene dicationic compounds. SSZ-41 appears to be closely related in structure to high-silica molecular sieve VPI-8 (VET framework type) but differs from VPI-8 in that SSZ-41 has an argon adsorption capacity greater than (e.g., up to about three times) that reported for VPI-8.
According to the present disclosure, it has now been found that zincoaluminosilicate SSZ-41 having high aluminum content can be directly synthesized from a combined source of silicon oxide and aluminum oxide selected from one or more of FAU framework type zeolite and a colloidal aluminosilicate.